This gaping hole in the Earth, seen from an incredible 17 miles above the surface, is what remains of the great volcano of Tambora. It’s located on the island of Sumbawa, in what is now Indonesia. This hole was blasted into the surface of the Earth exactly 200 years ago today, on April 10, 1815, in the largest single volcanic eruption in recorded history. This eruption was 10 times more powerful than the 1883 blast at Krakatau (Krakatoa), which is much more well known. Last summer I posted on this blog an eyewitness account of the Tambora disaster. It’s quite significant for me personally because the 1815 eruption of Tambora was the centerpiece–but by no means the sole cause–of a period of global rapid climate change called the “Cold Decade,” which was essentially a volcanic winter that lasted ten years, from 1809 to 1819. The bizarre weather and climate events of this decade, and especially people’s reactions to it, are the basis of my academic research, which (I hope) will eventually become a book entitled Ten Years of Winter.

Tambora is a very sad place from the standpoint of human history. At least 70,000 people died directly or indirectly as a result of the 1815 eruption, the vast majority of them indigenous peoples native to this area of what was then the Dutch East Indies (temporarily under British control). But even beyond that, this is a place where human civilization almost ended. Tambora was the largest volcanic eruption since the human race developed writing and records. There was, however, a previous eruption of another volcano called Toba–also in Indonesia–that happened about 75,000 years ago, when human beings and Neanderthals were still competing for evolutionary supremacy. There is evidence that the Toba eruption caused such a massive disruption to the world’s climate that it triggered mass extinction events all over the world–including of humans. Simply put, the Toba eruption killed 90% of the people then living on Earth.

Fortunately Tambora was not that bad, but if it erupted 200 years ago with the strength of the Toba event, the date April 10, 1815 would have been the blackest day in all of human history–because there would be a lot fewer of us around to remember it. This is the most chilling aspect of my research. Both Toba and Tambora are still technically active; Tambora last erupted in a small plume in 1967. After the blast that carved this crater it’s probably done for a while, but with the number of giant volcanoes in Indonesia surrounding it, a catastrophe on this scale is easily imaginable.